Image copyright EPA Image caption There have been indications in recent weeks that Rick Gates may be on the verge of a plea deal

A former aide to Donald Trump's presidential campaign is expected to plead guilty in a deal with the special counsel investigating ties to Russia.

Rick Gates was charged with conspiracy to launder money in October, along with his colleague and former Trump adviser Paul Manafort.

The LA Times and CBS News report that Mr Gates has now struck a plea deal with special counsel Robert Mueller.

Such a deal could see him agree to testify against Mr Manafort.

It is another key development in the investigation into possible ties between the Trump team and Russia. On Friday, 13 Russians were charged with interfering in the US 2016 election.

What are the charges?

The charges against Mr Manafort and Mr Gates do not relate to Mr Trump's campaign but to the alleged concealment of payments from the pair's Ukrainian business dealings up to 2016.

They are accused of acting as "unregistered agents" of Ukrainian politician Viktor Yanukovych and his party, both in opposition and government, and of acting to conspire against the US.

Mr Yanukovych was deposed as president in 2014 amid mass unrest over his pro-Russian policies.

Mr Manafort is accused of having laundered more than $18m (£13m) through offshore bank accounts, using it to buy property, goods and services in transactions concealed from the US authorities.

Mr Gates is accused of having transferred more than $3m from the offshore accounts to other accounts he controlled.

Both men pleaded not guilty to the charges. Last month, Mr Manafort launched a civil suit against Mr Mueller, alleging that the criminal case against him went beyond the special counsel's authority.

What is the latest?

There have been indications over recent weeks that Mr Gates may be on the verge of taking a plea deal. Earlier this month, it was confirmed he had changed his defence team for the second time.

News that he could reportedly have struck a deal with Mr Mueller was confirmed first by the Los Angeles Times, then by CBS News.

The LA Times said that Mr Gates' deal was likely to be announced in the coming days, and would see him getting a reduced prison sentence in return.

If that is correct, the terms of his plea are not yet known. But, much like George Papadopoulos, another former Trump aide who struck a plea deal last year, it is believed he would become a co-operating witness for Mr Mueller.

The LA Times said Mr Gates would help build the case against Mr Manafort.

What else is happening?

Media playback is unsupported on your device Media caption All you need to know about the Trump-Russia investigation

On Friday, it was announced that 13 Russians had been charged by Mr Mueller.

They are alleged to have:

Posed as Americans, and opened financial accounts in their name

Spent thousands of dollars a month buying political advertising

Purchased US server space in an effort to hide their Russian affiliation

Organised and promoted political rallies within the United States

Russia's foreign minister dismissed the charges as "blather" and President Trump said it was proof that there was no collusion between his camp and Russia.

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