Gerry Ryan in his 2FM studio

RTÉ management and the station's top stars closed ranks this weekend and refused to make any public comment on the revelations that cocaine was behind the death of Gerry Ryan.

The public service broadcaster issued a short statement sympathising again with Ryan's family, partner and friends, but made no reference to the Class A drug that triggered his heart attack last April.

RTÉ colleagues, who were quoted extensively and pictured repeatedly in the media at the time of his funeral, all either refused to comment or failed to respond to calls when they were asked if they were aware of Ryan's drug taking or if they had ever tried to intervene.

Household names Pat Kenny, Gay Byrne, Joe Duffy, Dave Fanning and Brenda O'Donoghue participated in Ryan Tubridy's Late Late tribute to Ryan on the day he died, sharing memories and swapping anecdotes. However, when contacted in the aftermath of Friday's inquest where a verdict of death by misadventure was recorded, all refused to speak of Ryan's years of sustained cocaine use.

Tubridy, Miriam O'Callaghan, Marian Finucane and Evelyn O'Rourke also declined to comment, as did President Mary McAleese, who issued a glowing tribute following the broadcaster's death eight months ago.

The head of the RTÉ press office, Kevin Dawson, failed to answer his phone yesterday despite being on call and other press office staff refused to take calls to answer claims that RTÉ's changed illness policy had contributed to the heart attack which ultimately killed Ryan.

The station was criticised this weekend for offering no analysis of Ryan's addiction, instead focusing on the tributes that have been paid to him. News programmes ran the inquest details, however all other RTÉ programmes virtually ignored the story and it has only been briefly mentioned in the station's daily review of the newspapers.

It is understood that some RTÉ presenters have had private conversations where they agreed among themselves to ignore the story, lest they be thrust into the media spotlight, but there was no officially agreed policy.

Joe Duffy, a well known anti-drugs campaigner, who was one of the most vocal supporters of Ryan after his death, made no mention of the inquest on Friday's Liveline and has this weekend gone to ground.

Medical evidence given to Coronor Dr Brian Farrell on Friday revealed that Ryan had a blood alcohol level of 158 microgrammes in 100 millilitres of blood – almost double the drink-drive limit. Pathologist Dr Eamon Leen, who gave evidence from Canada via Skype, said he found evidence of cocaine in the blood and urine of Ryan (53).

"Cocaine consumption has caused the toxic reaction to his heart. There is no other likely pathology that can explain this," he said. Dr Leen also found Levisamole, a veterinary medicine commonly found in cocaine, in Ryan's urine.

A spokeswoman for Ryan's estranged wife Morah yesterday refused to comment while
his partner Melanie Verwoerd also declined to speak to the media.