Washington - The computers of the House Democratic campaign committee have been hacked in an intrusion that investigators say resembles the recent cyber breach of the Democratic National Committee, a spokesperson for the committee said on Friday.Details were initially unclear about exactly who tapped into the computers and what information was accessed at the Democratic Congressional Campaign Committee. The organisation raises money and provides other assistance for the party's House candidates.President Barack Obama has said Russia was almost certainly responsible for the hack of the Democratic National Committee, an assertion with which cybersecurity experts have agreed. That breach led to the release by WikiLeaks on July 22 - just days before the Democratic national convention began - of 19 000 emails showing supposedly neutral party officials were favouring Hillary Clinton over Senator Bernie Sanders during their primary contest for the presidential nomination.As a result of that disclosure, party chair Debbie Wasserman Schultz, announced her resignation this week.Democratic Congressional Campaign Committee spokesperson Meredith Kelly said the organisation is using CrowdStrike, a forensic investigating firm, and is "co-operating with the federal law enforcement with respect to their ongoing investigation".A House Democratic aide said late on Thursday that the FBI is investigating the hack.Computer hacking, emails and indications of Russian involvement have evolved into a political issue in the presidential campaign between Clinton and Republican candidate Donald Trump. This week, Trump encouraged Russia to seek and release more than 30 000 other missing emails deleted by Clinton, the former secretary of state.Clinton deleted the emails from her private server, saying they were private, before handing other messages over to the State Department. The Justice Department declined to prosecute Clinton over her email practices, but FBI Director James Comey called her "extremely careless" in handling classified information.