Trump called Peter Strzok a 'sick loser' in his latest Twitter tirade just hours after the FBI agent agreed to testify in front of the House Judiciary Committee in the GOP's investigation into the Bureau's actions during the 2016 election.

The president renewed accusations that he's been the target of a 'Witch Hunt' in a series of tweets over the weekend, referring to special council Robert Mueller's investigation into possible obstruction of justice by Trump during the Russia probe.

This latest rant is in response to new reports about a previously undisclosed meeting between campaign officials and Russians.

One of the tweets slammed Strzok, who had briefly worked with Mueller on investigating possible collusion with Russia by the Trump campaign.

He was removed from the probe when it was revealed that he had sent politically-charged text messages criticizing Trump.

'Why was the FBI's sick loser, Peter Strzok, working on the totally discredited Mueller team of 13 Angry & Conflicted Democrats, when Strzok was giving Crooked Hillary a free pass yet telling his lover, lawyer Lisa Page, that 'we'll stop' Trump from becoming President? Witch Hunt!' Trump tweeted on Sunday evening.

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In his latest Twitter rant Sunday President Trump slammed Peter Strzok, who had briefly worked with Mueller on investigating possible collusion with Russia by the Trump campaign but was removed from the probe when a report revealed he had sent anti-Trump text messages

Strzok's lawyer has said the senior FBI official is willing to appear in front of the House Judiciary Committee in the GOP's investigation into the Bureau's actions during the 2016 election amidst allegations that it was biased against Trump

In a following tweet he added: '"The highest level of bias I’ve ever witnessed in any law enforcement officer." Trey Gowdy on the FBI’s own, Peter Strzok.

'Also remember that they all worked for Slippery James Comey and that Comey is best friends with Robert Mueller. A really sick deal, isn’t it?'

Strzok is one of the most senior officials in the FBI, having led the investigation of Hillary Clinton’s use of a private email server during her time as secretary of state and serving ad Mueller's number two in the investigation into whether the Trump campaign coordinated with Russia to influence the 2016 election.

A report from the inspector general released last week claimed Strzok had implied 'willingness to take official action' to prevent Trump's election, highlighting a text exchange between him and FBI lawyer Lisa Page in August 2016.

'[Trump’s] not ever going to become president, right? Right?!' Page wrote to Strzok.

He responded: 'No. No he won’t. We’ll stop it.'

As indicated by Trump's tweet, the two were romantically involved at the time, and had been using their work phones to communicate about personal and professional matters.

The president renewed accusations that he's been the target of a 'Witch Hunt' in a series of tweets over the weekend

The report from Michael Horowitz also suggested that Strzok's bias influenced the speed with which the investigation into Clinton's email was carried out in the fall of 2016.

On Friday it was reported that the House Judiciary Committee was gearing up to subpoena Strzok to testify in its investigation.

Strzok's lawyer Aitan Goelman sent a letter to the committee calling the subpoena 'wholly unnecessary'.

In the letter obtained by CNN Goelman wrote that his client 'has been fully cooperative with the DOJ Office of Inspector General' and 'intends to voluntarily appear and testify before your committee and any other Congressional committee that invites him'.

In an interview with CNN Goelman said: 'The kind of drumbeat — the repeated assertion of bias and the investigation was infected by ­anti-Trump bias — it’s completely illogical because the only thing that Pete and the FBI’s actions or inactions did throughout this period of time benefited Trump and hurt Hillary’s electoral chances.'

Goelman told CNN that his client 'intends to answer any question put to him, and he intends to defend the integrity of the Clinton email investigation, the Russia collusion investigation to the extent that that's a topic, and his own integrity.'

There was no collusion, there was no obstruction, and if you read the report you'll see that.

Experts have said that should Strzok appear before the Committee, he could expose even more about an alleged culture of bias in the FBI under Comey than what was in the nearly 600-page Justice Department inspector general report, which Trump referred to as a 'horror show'.

'Maybe more importantly than anything, it totally exonerates me,' Trump said of the report.

'There was no collusion, there was no obstruction, and if you read the report you'll see that.'

'What you'll really see, is you'll see bias against me and millions, and tens of millions of my followers. That is really a disgrace.'

Mueller is investigating whether Trump's firing of former FBI director Comey was an attempt to obstruct the Russian investigation.

When asked whether the report exonerated the president, House Oversight and Government Reform Committee Chairman Trey Gowdy said: 'It certainly helps him.'

Trump bragged that the report was evidence of his 'good instincts' on giving Comey the boot.

'The IG Report is a total disaster for Comey, his minions and sadly, the FBI. Comey will now officially go down as the worst leader, by far, in the history of the FBI,' he wrote. 'I did a great service to the people in firing him.'