Six blackmail investigations have been launched in Norfolk and Suffolk after people were threatened via email that explicit videos of them would be released.

Police have advised members of the public to change their passwords to all online accounts after the malicious emails were received.

It sees the sender claim to have explicit videos of the victim, and threaten to share them with their family, friends and colleagues unless a ransom of roughly $2,500 of Bitcoin - a cryptocurrency, a form of digital money - is sent.

Police have advised anyone receiving a blackmail message to not reply or part with money.

Six investigations are underway in Norfolk and Suffolk are emails were received by people in Woodbridge, Haverhill, Felixstowe, Ipswich, Thetford and King's Lynn between Tuesday, July 10 and Wednesday, July 18.

All six victims did not send money, and police say they have had no reports of the threat being carried out.

They say the emails are different to common phishing emails in various ways:

• The English is good

• The email contains an example of a password used by the victim

• The email contains a lot of detail

• There is a follow-up email sent after the 24-hour deadline for payment

It is believed that passwords have been obtained via a historic leak of data from an unknown website, and police have strongly recommended that members of the public change their passwords to all online accounts.

They suggest ensuring that all internet connected devices have anti-virus and anti-malware software installed and set to frequently scan for issues.

Officers have urged anyone who receives a message to call police on 101 or contact Crimestoppers anonymously on 0800 555 11.