Trump's sister calls him a 'liar' with 'lack of principles' in recording

US President Donald Trump's sister described him as cruel and a liar, whose lack of principles meant he could not be trusted.

These come courtesy of recordings published on Saturday.

His sister, Maryanne Trump Barry, is also the author of "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man".  

An online description of her book, says it reveals “a nightmare of traumas, destructive relationships, and a tragic combination of neglect and abuse.”

READ MORE: Trump family try again to halt tell-all book

Toxic Family

Maryanne slammed her brother over his immigration policy that saw children separated from their parents at the border and sent to detention centers.

"All he wants to do is appeal to his base," she said in recordings obtained by the Washington Post. 

"He has no principles. None. His goddamned tweet and lying, oh my God."

The recordings were secretly made by the president's niece Mary Trump, who published last month a bombshell memoir of the "toxic family" that produced him.

The president's younger brother Robert, who died last week, went to court to try to block its publication, arguing that Mary was violating a non-disclosure agreement signed in 2001 after the settlement of her grandfather's estate, but to no avail.

Mary, 55, speaking to the Washington Post, says her uncle is unfit to be president and she plans to do “everything in my power” to elect Joe Biden. 

Her father, Fred Trump Jr., died of an alcohol-related illness when she was 16 in 1981. 

In her book, she claims Trump and her grandfather mistreated her father.

Some 950,000 copies were sold the day of the memoir's release, with the White House calling it a "book of falsehoods".

Cruelty

At one point in the recordings, Maryanne said to her niece: "It's the phoniness of it all. It's the phoniness and this cruelty. Donald is cruel."

At one point her niece asked her aunt, “What has he read?”

“No. He doesn’t read,” Maryanne responded.

Fraud

The recordings also shed light on the source of an embarrassing claim in the memoir that the president paid someone to take a college entrance exam for him.

"He got into University of Pennsylvania because he had somebody take the exams," Barry said, adding she even remembered the man's name.

The transcripts show a deep rift between the president and his sister, illuminating a rift that began when she asked her brother for a favour in the 1980s. 

Ever since, Trump has frequently used that to try to take credit for her success.

Donald is out for Donald, period,” Maryanne said.

Mary questioned Maryanne about what he had accomplished on his own.

“I don’t know,” Maryanne said.

“Nothing,” Mary responded.

“Well he has five bankruptcies,” Maryanne said. (Trump’s companies have filed for six corporate bankruptcies, but he has never personally declared bankruptcy.)

“Good point. He did accomplish those all by his self,” Mary said.

“Yes, he did. Yes, he did. You can’t trust him,” Maryanne concluded.

The president or the White House did not immediately comment on the recordings.