A former campaign adviser to US President Donald Trump has been asked to testify before the House Intelligence Committee over accusations of Russian meddling in the 2016 election, the media reported on Sunday.

On Saturday, Michael Caputo, a campaign aide to Trump for much of the presidential primary, was asked to submit to a voluntary interview with the committee and provide any documents requested, the Guardian reported.

Caputo, who has close links with Roger Stone, Trump’s long-time and highly controversial political adviser, worked in Russia in the 1990s.

Democratic congresswoman Jackie Speier had previously mentioned Caputo’s name in a March hearing before the Committee.

Caputo worked for Trump’s campaign from November 2015 to June 2016 when he resigned after publicly gloating over the firing of former Trump campaign manager Corey Lewandowski.

In the immediate aftermath of Lewandowski’s termination, he tweeted: “Ding dong the witch is dead”.

Hours later, Caputo stepped down while expressing his regret for “too exuberant a reaction to this personnel move”.

The request comes as Trump is facing increased scrutiny over allegations about his campaign’s ties to Russia, reports the Guardian.

Former Federal Bureau of Investigation (FBI) director Robert Mueller has been appointed as a special counsel this week to investigate Trump’s campaign.

Former FBI Director James Comey was leading the investigation before he was abruptly fired by Trump on May 9.