A lone hacker stole a range of personal information from shipbroking giant Clarksons last year having infiltrated its computer system over a seven-month period, the company has revealed.

London-listed Clarksons called the police last November after learning of the cyber attack and has since secured a restraining order in the UK courts against the mystery hacker.

In a statement last night Clarksons detailed the timeline of the attack, a blackmail attempt, its work with forensic investigators and other response measures, alongside information on the type of data stolen.

The company said that while the information taken varied between individuals, it included date of birth, contact and medical information as well as CVs, insurance, driver's license and vehicle details and payment card and bank account information.

Details involving criminal convictions, visa and travel details, ethnicity, digital signatures and seafarer data was also listed.

Clarksons says it learned of the cyber-attack on 7 November 2017 and the hacker had accessed its system between 31 May and 5 November before demanding a ransom for the data’s safe return.

Forensic investigators found that the hacks had come from a single account which was shut down.

A copy of the stolen data has now been traced and those potentially impacted are being notified, the statement added.

Clarksons said it takes “security of personal information very seriously” and has enhanced security measures in place.

It is also paying for one year of identity protection services for those affected.

Shares in the shipbroker were trading up 0.20% at £25.40 each at the time of writing on Tuesday.