In Washington DC, politicians are bracing for more embarrassment after the 'lone wolf' hacker known as Guccifer 2.0 claimed another batch of internal emails and files relating to the Democratic Party had been sent to whistleblowing organisation WikiLeaks for release.

The 'major trove' of documents, as described by Guccifer 2.0, are reportedly from the Democratic Congressional Campaign Committee (DCCC) – a group that handles donations for democrats running for the US House of Representatives.

The threat of a fresh disclosure follows a partial release of DCCC data on 12 August that exposed email addresses and phone numbers of nearly 200 political figures.

On the same day as the data was released, Guccifer 2.0 – which many believed is a persona controlled by Russian intelligence - promised more was on the way.

The Twitter account linked to the hacker stated: "#Guccifer2 I'll send the major trove of the #DCCC materials and emails to #WikiLeaks keep following..." After the message, the account was temporarily suspended and the website post hosting the data dump was removed.

Last month, WikiLeaks released 20,000 emails allegedly stolen from the computer systems of the Democratic National Committee (DNC) that resulted in a number of high-level resignations. Despite Guccifer 2.0 taking credit for their submission, the group's founder, Julian Assange, has so far refused to comment on the source of the data.

This is most likely due to Guccifer 2.0's reported links to the Russian government. After the DNC emails were made public in a searchable database, WikiLeaks received significant backlash after critics claimed it had been 'weaponised' by the Kremlin.

To date, the leaks have largely focused on the US Democratic Party – with Hillary Clinton, its presidential nominee in November's election targeted. However, fears are growing within the Republican Party that its members may also have been targeted.

The appearance of a little-known website called DCLeaks – which has been linked to Guccifer 2.0 in the past – only complicates matters. While the site claims to have been launched by "American hacktivists" researchers from cybersecurity firm ThreatConnect believe it is a "Russian-backed influence outlet".

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Former U.S. Secretary of State Hillary Clinton speaks to the media after a keynote address at a Women's Empowerment Event at the United Nations March 10, 2015 in New York City Yana Paskova/Getty Images

The day after Guccifer 2.0 published the DCCC files, the DCLeaks website released internal records from Open Society Foundations, a liberal group led by George Soros. The website also hosts data supposedly hacked from Air Force General Philip Breedlove – a former high-profile Nato official – and DNC staffer Sarah Hamilton.

In previous correspondence with IBTimes UK, Guccifer 2.0 provided a username and password to access secure files on DCLeaks but denied links with the project. "This isn't my work, they gave me password-protected access," the hacker said at the time.

However, it is the appearance of internal emails from the Republican Party that indicates recent political hacks are not confined to the Democrats. In one post from April, DCLeaks published emails from a wide variety of GOP members.

"Everyone is sweating this"

In light of this, one person closely connected to the investigation of the Democratic Party hacks recently told The Daily Beast on condition of anonymity: "Everyone is sweating this right now. This isn't just limited to Democrats."

Pictured: Screenshot from DCLeaks website, suspected to be the work of Russian intelligence DCLeaks/Screenshot

On closer examination, ThreatConnect found DCLeaks was hosting content that was breached using similar tactics employed by Fancy Bear – one of the two Russian state-sponsored groups believed to have hacked into DNC networks. Furthermore, researchers said the websites' registration and hosting data also linked it to the same culprits.

"DCLeaks provides Russia with another platform that they can use to hide their hand and conduct influence operations in the US," it said in a blog post. "Such operations may ultimately help Russia sway public opinion or media coverage in a way that benefits Moscow."

The FBI, which is investigating the hacks and leaks from Democratic Party-related groups and politicians, has been forced to broaden the scope of its probe after it emerged the hackers' campaign targeted 'more than 100' political figures.

Yet while the Obama Administration has declined to place direct blame for the infiltrations, Hillary Clinton has been less subtle in attributing the hacks to both the Russian state and Putin's intelligence services.

"We know that Russian intelligence services, which are part of the Russian government, which is under the firm control of Vladimir Putin, hacked into the DNC. We know that they arranged for a lot of those emails to be released," Clinton said in an interview aired on 31 July.

Officials close to the Kremlin continue to deny any role in the hacks.