A spokesperson for Prime Minister Najib Abdul Razak has reportedly confirmed the family feud that led to his stepdaughter Azrene Soraya Abdul Aziz openly rebuking her brother Riza Aziz.

The unnamed spokesperson told The Weekend Australian on Saturday that he had seen Azrene Soraya's posting on her Facebook and Twitter accounts.

“She has a right to say what she wants to say but I can say for sure that the mother and daughter have been estranged for many years.

"We are not responding to it at the moment,” he was quoted as saying, adding that it was a private family matter.

Azrene had said that her estranged brother Riza, who is named in the US Department of Justice's (DOJ) asset forfeiture filing, is reaping what he sowed for selling his soul to the devil.

This follows the DOJ's civil suit to seize US$1.3 billion in assets allegedly misappropriated from state investment fund 1MDB.

The 136-page document, among others, identified Riza as a central figure in the civil forfeiture suit.

Riza had previously denied that his production company, Red Granite Pictures, had received funds from 1MDB.

However, the latest court documents stated that Red Granite had received US$64 million that was traced back to 1MDB.

In response, Red Granite said it had no reason to believe the money used to fund the production of 'The Wolf of Wall Street' was “illegitimate” and that these latest claims would not affect its operations.

Najib had consistently denied any wrongdoing and was not named in the US DOJ suit, although it made 36 references to "Malaysian Official 1".