THE FBI have joined the investigation after a suspicious package sent to Romsey's MP brought the town to a standstill two months ago.

The office of Romsey and Southampton North MP Caroline Nokes was quarantined in April after a potentially dangerous substance was found within a letter sent to the Immigration Minister.

Now, after launching a probe to catch those responsible, Hampshire Constabulary have teamed up with the Federal Bureau of Investigation in the United States, after suspicions arose that the package came from America.

MP Caroline Nokes said that every effort would be made to catch those responsible, wherever in the world they were.

She said: "My message to anyone who thinks it is acceptable to cause such disruption is that every effort will be made to catch you, no matter where you live.

"I am very grateful to Hampshire Constabulary for their hard work in progressing the case and I am glad to hear that US authorities are taking this seriously.

"My staff should never have to go through such a horrendous experience, not to mention those who were simply in the building at the time."

A spokesperson for Caroline Nokes confirmed that the police are exploring the possibility that the letter originated from a sender in the United States, and that officers are working with the FBI to try to identify the sender.

The MP's office, which joins the Conservative Club, was shut off for four hours on April 17. Market Place was closed in all directions as police, fire crews, ambulance staff and forensic officers swarmed the building.

Staff inside the office, who opened the letter in the absence of MP Nokes, who was in London at the time, said the letter looked immediately suspicious.

A staff member said at the time: "It was very worrying, it's not something we're used to and it came as a shock."

The letter contained a coloured powder, that police later confirmed as brown, but was ultimately tested and found to be harmless.