A teacher at St Mary's Music School in Edinburgh was struck off yesterday following his conviction over a nine-month sexual relationship with a 15-year-old boy.
The General Teaching Council Scotland also recommended Scottish ministers ban Ashley Turnell, 36, from working with children.
Turnell was convicted at Edinburgh Sheriff Court last December and given probation, community service and placed on the sex offenders register.
Lord George Foulkes, MSP for the area, has now demanded an inquiry from education minister Mike Russell.
Last October, Jamieson Sutherland, 41, a singer in St Mary's choir and a music teacher, was jailed for 18 months after he was caught with more than 4,000 child porn images on a computer.
It is not clear whether or not Sutherland, 41, was employed by the school but he was a singer in the choir, which includes several pupils.
And in July this year, a house- parent at St Mary's, Ryan Deneven-Lewis, was given probation after he groomed two teenage girls at the school.
Deneven-Lewis, 27, admitted using lewd, libidinous and indecent practices and behaviour towards a 15-year-old and to having sexual intercourse with the 16-year-old while in a position of trust.
Lord Foulkes said: "I have written to education minister Mike Russell, asking him to investigate these cases which have been drawn to my attention and, if concerned parents contact me, I will take up individual cases and also pursue any general concerns they express to me."
Turnell was caught after another staff member tipped off the school, and he confessed to grooming the boy between December 2007 and August 2008.
He was placed on the sex offenders register for three years after admitting abusing his position of trust and having sexual intercourse with the boy, who cannot be named.
Striking him off, convener of the GTC's disciplinary sub-committee Freida Fraser said: "We decided to direct that the registrar remove the respondent's name from the register.
"In arriving at this decision, members took into account the other options open to it.
"To consider any other option than removal would not have been appropriate in the circumstances of this case, given the serious nature of the crime and that it constituted a significant breach of trust and actual harm to a child.
"The public and the profession expect and indeed deserve that such breaches of trust are addressed with due rigour.
"The sub-committee decided the respondent's name should be referred to the Scottish minister for consideration for inclusion on the list of those disqualified from working with children."
A spokeswoman for St Mary's said the school always carried out the relevant disclosure checks, and insisted student safety was a top priority.
She said: "The school's responsibility to personal information must be complied with and we are therefore unable to disclose any further information."
On its website the school, in Grosvenor Crescent, Edinburgh, is described as "one of the UK's leading specialist music schools" providing "a unique education for children with a special talent".
Last night, it emerged that Lothian and Borders Police, the Care Commission and HM Inspectorate of Education (HMIe) were all looking into events at the school.
A spokesman for the inspectorate said: "HMIe is aware of the situation at St Mary's. However, our colleagues at the Care Commission are investigating the issues and HMIe are content to allow them to carry out the investigation."
A police spokeswoman said: "Lothian and Borders Police have fully investigated each incident individually, and worked with our colleagues at the school to offer support throughout."