The country is being left behind by major rivals due to a lack of facilities and funding, and film-makers and crew are increasingly forced to work overseas to make a living, it said.
The unpublished report, commissioned by Creative Scotland, said there was an urgent need for a long-term strategy to revive the flagging industry.
Consultants who spent more than a year quizzing industry figures said a lack of studio facilities meant it was unable to sustain a big-budget production in future, and warned that any permanent venture would need a public subsidy to keep it running initially.
There are strong suggestions the only prospect of a revival for the film industry is as a spin-off from a boosted TV sector.
However, the report is highly critical of the Scottish Government, BBC and STV for not doing enough for the wider “screen sector”, while national funding agency Creative Scotland is criticised for insisting on a “return on investment” from home-grown films.
The study says just three “Scottish” films in the last several years have had major success – The Last King of Scotland, The Illusionist and The Angels’ Share.
The report, largely compiled before such recent Scottish hits as Filth and Sunshine on Leith, states: “Scotland’s film industry makes too few films to be a potential engine for success.”
The consultants, BOP, said they found “general agreement” during the consultation process that Scotland lacked a “stable and sustainable film industry”.
Among those involved in the process were Alan de Pellette, acting director of BAFTA Scotland; Ken Hay, chief executive of Edinburgh International Film Festival; screenwriter Andrea Gibb; and director Zam Salim.
The report adds: “Many contributors cited a lack of infrastructure, investment and development funding as causing a loss of talent to other areas and countries where there is a more vibrant sector. Many commented on the reliance of film production in Scotland on lottery funding, rather than Scottish Government funds, and saw this, alongside the requirement to make a return on investment to Creative Scotland, as indicating film is treated differently from other art forms.
“The last cluster of successful Scottish films before the current batch dates from the mid-late 1990s. While there is no guaranteed formula for a hit film, Scotland needs to make more films if it wants to produce more hits.
“Setting a target to produce significantly more – say, 12 in five years’ time – might be a useful approach.”
The report says there is “no strategic commitment” from STV or BBC Scotland to back the development of home-grown film, adding: “Lack of airtime is an issue and frustrates those whose work could, they feel, reach an audience in Scotland.”
The report adds: “Inward investment production is vital for jobs, as is television production from both international and UK broadcasters. All need strategic support to develop and thrive.
“This mixed economy is essential if film is to be sustained within the screen sector. Film alone is unlikely to generate sufficient business to maintain an industry.
“It may well be that the development of high-end television capacity, alongside existing local television, becomes the most likely source of sustainable income for the screen sector in Scotland, with film being a minor, if important, part of the sector’s revenue streams.”
A spokeswoman for Creative Scotland said the final report on the film sector would not be made public until January.
Earlier this week MSPs were warned the Scottish film industry had slumped into a “terrible state” since the scrapping of film agency Scottish Screen in 2010, when it was merged with the Scottish Arts Council to form Creative Scotland.
• Attendance at cinemas has risen steadily over recent decades and Scots have become some of the keenest cinema-goers in Europe.
• From directors such as Alexander Mackendrick, Bill Forsyth and Lynne Ramsay to actors like Sean Connery, Ewan McGregor and Tilda Swinton, Scots have helped define the possibilities of cinema.
• Perhaps only Braveheart, below, in the last two decades can be said to have significantly shaped the ways Scots see their country.
• Glasgow Film Festival and Edinburgh International Film Festival face infrastructure problems which hamper their ability to grow.
• Scotland has produced few films in the last five years or so that have achieved significant success. Exceptions have been The Last King of Scotland, below, The Illusionist and The Angels’ Share.
• Scotland’s film industry makes too few films to be a potential engine for success.
• Scotland needs to make more films if it wants to produce more hits.
• Of the top 30 Lottery awards distributed by the BFI in 2011-12, two related to Scottish productions – Sunshine on Leith, left, and Under the Skin.
• A sustainable industry would need greater funds and a review of funding strands.
• The lack of large-scale studio space has a detrimental effect on Scotland’s ability to attract big-budget productions.
• The lack of production infrastructure is especially lamented by crew for whom the knock-on effect is lack of employment in Scotland.
Scotland boasts 64 cinemas with 337 screens.
An average of just six indigenous Scottish films are produced each year.
Creative Scotland offers a maximum of £300,000 to film productions.
At least 34 film festivals were due to be held in Scotland this year.
Scotland is responsible for just 1.2 per cent of turnover of UK production companies.
Only 62 people work full-time in film production.