Nigel Farage has suggested that there was “Russian collusion” among the 3,200,000 people who have signed the “Revoke Article 50” petition.
On Friday afternoon the petition, which calls for Article 50 to be revoked so that the UK can remain in the EU, had been signed by 3,238,126 people.
Mr Farage tweeted data that appeared to show the petition had been signed by people in countries such as Russia and Spain.
Alongside the data, Mr Farage said: “Russian collusion, we need an enquiry here.”
People signing the petition on the Parliament website are asked to tick a box saying they are a British citizen or UK resident before they sign.
They are also asked to confirm their name, email address and postcode.
Data from the petitions website on Friday afternoon suggested 1.3m signatures were people who said they were from the UK, 10,000 from France, nearly 6,000 from Spain and over 1,000 from Italy.
The data shows 28 signatures from Russia.
A Commons spokesman said signature patterns are investigated to check for fraudulent activity, including those that are “bots”.
He added that suspect signatures are removed.
He said: “Anyone who is a UK resident or a British citizen can sign a petition. This includes British citizens living overseas.”