Detectives do not yet suspect the drug boss was responsible for the fatal shooting, but will seek to speak to him.
The trafficker lives on Kippure Park in Finglas, west Dublin, the same road where Walsh was gunned down.
“We will speak to him as part of our house to house inquiries. Whether he will volunteer any information is another thing,” said a Garda source.
Although he had 47 convictions, Walsh was not considered a serious criminal.
A recovering heroin addict, the 33-year-old was shot dead at the front garden of a house on Kippure Park at 12.20am on Saturday.
He had only been given temporary release from Mountjoy Prison on Thursday, where he had three weeks left for a hijacking offence. He had already served a related firearms offence.
Prison sources yesterday said Walsh had been released three weeks early as he had made good progress in dealing with his drug addiction and had good family support.
Detectives were in Mountjoy Prison yesterday where they have started investigating whether Walsh was involved in any feud with prisoners there.
Gardaí said there was no evidence yet to support reports that Walsh assaulted a prisoner last April.
“The investigation is ongoing, but we’re not aware of any threats to his life and he doesn’t seem to have got into a row since he was released,” said the Garda source.
However, some local sources yesterday suggested Walsh had been in a row with three men at the scene where he was shot earlier in the night.
However, gardaí said Walsh was in the house of a neighbour of his on Valley Park Road up to an hour before he was killed.
Local sources claimed yesterday the road where Walsh was shot had a long-running problem with street dealing and that a number of families in the area were involved.
One source suggested Walsh may have trying to re-establish himself as a drug dealer and could have crossed local suppliers.
Gardaí said they will try to talk to all of these families in their local inquiries.
Detectives will also investigate the link with murdered crime boss John Daly, who was gunned down last October two months after being released from prison.
Walsh was a close associate of Daly and fellow murdered crime figure Declan Curran.
Gardaí said Walsh’s gunman arrived and left on a bicycle and was aged in his mid-to-late 20s. They suspect he got off the bike nearby, where they feel he had assistance in fleeing.