A laptop belonging to the rail minister was reportedly stolen from a pub earlier this month, with confidential information about train strikes contained on it.
Sensitive information relating to negotiations over the then-recent strikes was contained on it at the time, but was wiped remotely once the theft was raised with police, sources said.
The reported theft from the pub on James Street came just a day after the biggest rail walkouts for more than a decade.
RMT and Aslef workers at 14 train companies took industrial action on February 1 and 3 in a dispute over pay and conditions, which continues.
Sources told the Standard that Mr Merriman, the Conservative MP for Bexhill and Battle, told the police about his stolen laptop at around 7.30pm, with the Metropolitan Police confirming the theft was reported to them.
However, they said no arrests had yet been made.
A government spokesman said: ‘We take the security of government devices extremely seriously, which is why devices, such as laptops and mobile phones, are always encrypted so any loss does not compromise security.’