BOSTON – The former head of an agency that received taxpayer dollars to help special needs students is facing allegations that he used his control of the education collaborative and a related nonprofit to boost his pay and the pay of a handful of top executives and a former girlfriend.

State Inspector General Gregory Sullivan said John Barranco, the former director of the Merrimack Special Education Collaborative, also used the credit card of the nonprofit he established to charge what appear to be more than $50,000 in personal expenses.

Sullivan said Barranco also used the same construction firm simultaneously for work for his nonprofit Merrimack Education Center and for work on his home.

A call to Barranco was not immediately returned. The investigation was first reported by The Boston Globe.

Sullivan said that under Barranco, the Merrimack Education Center had a history of paying high salaries and bonuses to a handful of top officials at the nonprofit and the collaborative.

Barranco received well over $1 million in bonuses between 2003 and 2009 according to the nonprofit’s records, Sullivan said.

Sullivan said that Barranco also put lobbyist Richard McDonough on the collaborative’s payroll at $80,000 a year as director of public affairs and government relations.

During that time, according to Sullivan, McDonough did not have an office or telephone at the agency and representatives of the collaborative could point to no work that McDonough did.

“It was literally a no show job,” Sullivan said in a letter to the Merrimack Education Center.

McDonough’s lawyer has told The Boston Globe that his client denies any wrongdoing. McDonough was recently convicted along with former Democratic House Speaker Salvatore DiMasi on federal corruption charges in an unrelated case.

Among the personal purchases that Barranco allegedly put on the nonprofit’s credit card were trips to the Kentucky Derby, cigars and poker chips, clothing and a robotic pool cleaner.

Sullivan also wrote a letter to the Massachusetts Teachers Retirement System saying his investigation raised fundamental questions about the validity of Barranco’s public pension, worth more than $155,000 a year.