A leading agency that works with victims of sexual abuse has criticised the "leniency" of the sentencing of a prominent Irish writer and questioned the influence novelist Colm Tóibín's character reference had on the case.

Last week, writer Des­mond Hogan was given a two-year suspended jail sentence after he pleaded guilty to sexually assaulting a 15-year-old boy. He was also placed on the sex offenders' register and ordered not to have unsupervised contact with children. Dr Niall Muldoon, national clinical director with Cari, said: "There may have been an element of leniency because of who he was. A character reference from a leading Irish writer could have been a strong influence. I think he should have got a custodial sentence."

Ballinasloe-born Hogan (58), who formerly lived at Back Lane, East End, Ballybunion, Co Kerry, had pleaded guilty at Tralee Circuit Criminal Court in July 2008 to sexually assaulting the 15-year-old on 11 November 2006, at a house he was renting in the seaside town.

The court heard a statement from Colm Tóibín, who described Hogan as a writer "of immense power and importance who dealt with human isolation". Contacted last week, Tóibín said he stood over his decision to issue a statement to the court. "I merely explained who Desmond Hogan is. It was a standard character reference. If anyone takes it any other way, it's foolish of them," he told the Sunday Tribune.

Dr Muldoon said he had concerns that publicity surrounding the case could have a negative knock-on effect and discourage children suffering abuse from coming forward. "The perception is that if someone like Colm Tóibín writes a letter for you, you can end up with a suspended sentence. The perception for children is that 'I can't go up against someone who has a reputation'.

"If a child is suffering and they see this case on the news, they could think, 'why would I bother?' If he was one of the best carpenters in the country, would that have made a difference?

"The perception is that if someone is in the public eye and is seen to do a good job, the crime can be mitigated," he added.

The director of One in Four, Maeve Lewis, said she did not wish to comment on the Hogan case but added: "I don't think the achievements in a person's life should have any bearing on the sentence imposed."