Bernard Madoff’s son Mark was found dead in the living room of his SoHo apartment this morning — hanging from a black dog leash on the two-year anniversary of his father’s stunning downfall, officials said.

Officers were called to 158 Mercer St. at 7:28 a.m. after Mark’s father-in-law reported the grisly find — the 46-year-old Madoff hanging fully clothed from a pipe in the apartment ceiling, police said.

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His 2-year-old son Nicholas was sleeping in a nearby bedroom and was unharmed, as was Grouper, their labradoodle.

It was Mark and younger brother Andrew who first heard their dad’s astonishing confession — and dropped a dime to the feds on one of the biggest investment fraud schemes in history.

“No one wants to hear the truth,” the despondent 46-year-old scion wrote his lawyer in one of three wrenching emails dispatched around 4 a.m., a law enforcement source told The Post.

“Take care of my family.”

In two messages sent to wife Stephanie he said, “I love you” — and then alerted her to “send someone to take care of Nick,” the source said.

A freaked out Stephanie — at Disney World in Orlando with her mom and 4-year-old daughter, Audrey, at the time of the suicide — then dispatched her father, high-powered lawyer Martin London, to the apartment in the swank building that’s home to rocker Jon Bon Jovi.

London made the grisly discovery and called 911, said police sources.

No note was found with Madoff’s body; he was clad in khaki pants, blue pullover shirt and white socks, sources said.

The eldest son of Bernie, Mark was “upset” over the two-year anniversary media coverage of his father’s massive fraud and subsequent arrest on Dec. 11, 2008, the source said, noting a front-page story of the scheme and its aftermath in today’s Wall Street Journal.

The source said London had told cops Madoff had gotten a heads-up the article was going to run. The story was posted on-line by midnight.

But London also told cops his son-in-law had already been disturbed about events in the case — though never, he thought, to the point of suicide, the law enforcement source said.

Cops are trying to get a subpoena for Madoff’s computer and check its contents, including his e-mails, other sources said.

“It’s a terrible and unnecessary tragedy,” said Mark Madoff lawyer Martin Flumenbaum.

“Mark was an innocent victim of his father’s monstrous crime who succumbed to two years of unrelenting pressure from false accusations and innuendo.”

The stunning twist in the Madoff saga came two years to the day after Bernie Madoff was arrested for running a pyramid scheme that bilked some $65 billion from gullible investors all over the world.

The elder Madoff was sentenced to 150 years in prison.

“He was under a lot of pressure with the slew of lawsuits filed this week … the slew of media coverage dragging his name through the mud,” said another source familiar with the matter.

“He had been increasingly upset. It’s been a hard two years for him, especially with the second anniversary of his father’s arrest.

“He was in a tough place.”

Yesterday, Madoff dropped off an early Christmas gift to Mercer Parking garage attendant Anthony Diaz, 37 – a festive card with $400 and a handwritten message to five attendants who parked his black 2008 Land Rover.

“He’d do it every year, but this year he did it early,” Diaz said. ‘He’d give it to us around the 20th. I thought he gave it to us early because he was going on vacation.”

They took the card – decorated with three penguins – down from the wall this morning.

Mark Madoff was “unalterably bitter” over his father’s decades-long deception, a spokesman told the Wall Street Journal recently.

As The Post reported in 2008, neither Mark nor Andrew would even sign their names to help bail him out of jail after his arrest.

The eldest Madoff scion is believed to have cut off all contact with both his dad and mom Ruth — who now is believed to be living with her sister in Florida —since the massive scandal.

Mark and his brother, Andrew, were sued this week by Irving Picard, the court-appointed trustee recovering assets for the Bernard Madoff’s victims.

The two brothers were brokers in their father’s firm, and have said repeatedly they didn’t know of their father’s crimes.

Neither has been charged criminally, nor are charges imminent, a source familiar with the matter told The Post.

Midnight tonight is the deadline for Picard to file any lawsuits to try and claw back funds that can be distributed among Madoff’s victims.

“This is a tragic development and my sympathy goes out to Mark Madoff’s family,” Picard said in a statement today.

Yesterday, Picard filed blockbuster civil suits in Manhattan bankruptcy court seeking $19.6 billion in damages.

Picard’s latest suit focused on Austrian banker Sonja Kohn, who is accused of funneling money to feed Madoff’s Ponzi machine in Europe. Kohn had portrayed herself as a victim of Madoff’s thefts.

Madoff’s wife Stephanie, who legally changed her surname to Morgan from Madoff, as well as those of her two kids Audrey and Nicholas — citing “certain death and other threats made against the Madoff family” in her court petition in February.

He is survived by his son with Morgan, and the two children with his former wife, Susan Elkin of Connecticut, who today declined to comment on the tragedy.

Mark had nearly gone off the rails at least once before — in October 2009.

Stressed-out, he went briefly missing after a bitter argument with his wife, who then frantically called police, fearing for his safety, The Post reported at the time.

It was later learned that he’d spent the night in a posh hotel, paying in cash, and that he’d intended to seek help from a doctor, sources said at the time.

Known as the outgoing frontman at his dad’s firm, Mark also was reportedly prone to depressive mood swings and physical ills, including stomach troubles.

Mark and Andrew Madoff were the first people to hear dad Bernie’s confession to the incredible fraud scheme.

According to legal documents, the senior Madoff told Mark and Andrew of the scam on Dec. 10, 2008 – reportedly calling the scheme “one big lie.”

Additional reporting by Kirsten Fleming, Georgett Roberts, Candice M. Giove and Dan Mangan