A plumber who worked at the East Village building where two people died in an explosion last month has admitted to illegally tapping into a gas line there — but said the landlord’s son ordered him to do it, The Post has learned.

The unidentified tradesman confessed to rigging a gas-supply system for apartments at 121 Second Ave. but blamed it on his boss to “deflect” any fault from himself, law enforcement sources said.

Authorities haven’t decided whether to cut a deal with the worker in exchange for his testimony or use his statement against him, one source said.

The official investigation is still in its preliminary stage, with probers trying to recover evidence from the rubble, sources added.

Investigators suspect an illegal hookup in the building was removed from a gas line ahead of a Con Ed inspection on the day of the explosion, then reinstalled before the devastating blast about 30 minutes later.

The building’s landlord has been identified as Maria Hrynenko, who inherited it and several others from her late husband, Michael Sr. The husband ran the East Village’s iconic 24-hour Kiev diner before his death in 2004.

Authorities have said the couple’s son, Michael Jr., 29, was at the building before the explosion, along with general contractor Dilber Kukic of The Bronx.

Michael Hrynenko Jr., also called “Mischou,” was hurt in the blast and carried to safety by Kukic.

Kukic is awaiting trial on bribery charges in a sting involving an undercover officer who posed as a crooked city housing inspector.

There was no answer at Michael Hrynenko Jr.’s nearby apartment Sunday, and he didn’t return messages left on his voice mail and in a note at his home.

A woman who peered through a window at his mom’s home in Rockland County said Michael Jr. wasn’t there. She did not answer any other questions.

A lawyer who last week spoke on behalf of Maria Hrynenko declined to comment Sunday. Sources have said she is also under investigation.

The lawyer, Thomas Curtis, said he was replaced Thursday by a “local lawyer from Dutchess County” but was told by Maria “not to give out his name.”

“It wasn’t working out between us,” Curtis said. “The whole thing is very strange. I think she’s made a mistake.”

Maria didn’t return a voice-mail message seeking comment.

The March 26 explosion ignited a massive fire that destroyed the five-story former tenement and two other buildings.

Last week, two bodies were pulled from the rubble and identified as Nicholas Figueroa, 23, of East Harlem, who was on a date at the ground-floor Sushi Park restaurant, and busboy Moises Locon, 27, of Queens.

On Sunday, several NYPD vehicles and emergency tents remained near the barricaded blast site, but work was suspended for the Easter holiday, cops said.

Sources have said anyone suspected of causing the devastation, which injured more than 20 people, could face charges including second-degree manslaughter and reckless endangerment.

Additional reporting by Priscilla DeGregory