The Scottish Government said a taskforce set up to consider the issue has completed its work and its findings will be published within weeks.
Campaigners have previously highlighted the "extraordinary" timeline of delays over the proposals, with the idea first mooted more than a decade ago.
There are ongoing concerns over the illegal killing of birds of prey in Scotland. Expanding the Scottish SPCA's current powers would allow it to investigate cases involving animal deaths and illegal traps.
Conservationist Dr Ruth Tingay, author of the Raptor Persecution UK blog, said she had been tracking the debate for 11 years, "watching a succession of eight environment ministers kick it into the long grass".
She said: "I hope the recommendation of the taskforce brings this excruciatingly embarrassing saga to an end and that the Scottish SPCA is given increased powers to enable its officers to work in partnership with the police and other agencies to finally get a grip on the illegal killing of birds of prey.
"These disgraceful wildlife crimes continue because the perpetrators know fine well the chance of being caught and prosecuted is minuscule. There is no deterrent.
"The involvement of experienced officers and investigators from the SSPCA will, I'm certain, have a significant impact on bringing those responsible to justice".
Green MSP Mark Ruskell said the move would be a "crucial step forward". He proposed new powers for the Scottish SPCA as part of legislation in 2020, but the Scottish Government instead committed to setting up an independently-chaired taskforce to consider the issue. This was then delayed.
Last year, the Government said the group would report before the end of 2022. The taskforce formed part of the co-operation agreement between the SNP and the Greens.
Mr Ruskell said: "The present system is not working, and the only ones benefiting from it are the criminals.
“The reality is that wildlife crime has been rife for years, but overstretched police have been unable to take the action that is needed. This has only allowed it to continue unabated.
"Every other option that has been tried to improve the detection of wildlife crime has failed. At a time when policing budgets are under increasing strain this is the only practical way forward.
“For far too long, Scotland has had to endure persecution of birds of prey and other iconic species.
“We have been calling for the SSPCA to have additional powers for a long time and pushed for it in Bute House [co-operation] agreement negotiations. After years of delays, I hope that we can finally make it a reality.
Scottish SPCA Chief Superintendent Mike Flynn said: “We are pleased that the consideration to award powers to the Scottish SPCA under the Wildlife and Countryside Act 1981 have come to a conclusion. We have committed to help the Scottish Government combat wildlife crime following a suggestion made in 2010 by Peter Peacock MSP. We look forward to reading the findings of the plans over the coming weeks.”
A Scottish Government spokesman said: “We take animal welfare very seriously and in recent years have introduced a variety of measures to combat wildlife crime.
“We committed to set up a taskforce that was to consider whether the Scottish Society for the Prevention of Cruelty to Animals should be given extra legislative powers to investigate wildlife crime. The taskforce has completed its work and its report will be published in due course.”