Story highlights Lady Gaga accuses the blogger of stalking her after he house-hunts at her NYC building

Hilton says he learned later that her building was among those he looked at Sunday

The former friends have not said why they had a falling out

The latest celebrity Twitter feud erupted Sunday between two heavyweights of the social medium.

In one corner: pop superstar Lady Gaga and her nearly 40 million followers. In the other: pop culture blogger Perez Hilton and his 6.1 million Twitter fans.

Who won the war of 140 characters? It depends on whom you ask.

The feud between the former friends appears to stem from several incidents: Hilton tweeted Thursday that Katy Perry's new single, "Roar," is better than Gaga's latest song, "Applause." On Friday, Gaga, who is in the midst of a comeback following a serious tear to her right hip, cryptically referenced a text from Hilton that appeared to make light of her injury. "Still have the text Perez sent me of me in a wheelchair with the words KARMA written across + Madonna pointing a gun at me," she tweeted.

But Gaga went into Twitter overdrive Sunday, accusing Hilton of stalking her, after one of her followers alerted her that he was at Gaga's apartment building in New York.

"STAY AWAY FROM ME + MY FAMILY YOU ARE SICK TRYING TO RENT AN APARTMENT IN MY BUILDING TO STALK ME. LEAVE ME ALONE!!!" she tweeted.

Hilton, who lives in Los Angeles, announced last week that he is moving to New York as he raises his new son, born via a surrogate in February.

He responded to Gaga's tweets with a post on his blog Sunday night, titled "A Statement On Lady GaGa's Lies." In the statement, he explains he was house-hunting and later learned one of the buildings he looked at was, in fact, Gaga's building.

"After a day of innocent house-hunting, I am devastated and my heart hurts that my former very good friend, a person I used to call my 'wifey' and traveled the world with, is making very public and very untrue allegations about me on Twitter," he wrote, adding "it is still too painful" to reveal what caused the end of their friendship.

He said that as a result of Gaga's series of tweets Sunday, her fans have sent him death threats and posted derogatory comments about his 6-month-old son.

"If her fans want to send a message of support to Lady GaGa, they should buy her music," he wrote, a thinly veiled reference to Gaga's new single being declared a flop by several media outlets.

And while Gaga vowed "I've been quiet for a long time, not this time," Hilton appeared to be getting the last word.

"The truth will all eventually come out. It usually does!" he wrote.