POLICE HAVE ARRESTED a man suspected of hacking into the website of a major British abortion provider, vandalising it and stealing sensitive data, officials said Friday.

The British Pregnancy Advisory Service, which has around 40 clinics and other centers across the country, said the hacker wasn’t able to access medical information about women who had sought treatment from the nonprofit organisation.

However the attacker was able to compromise about 9,000 records — including names, addresses, and phone numbers — of people who had made inquiries through the website. Public policy manager Abigail Fitzgibbon said that swift action by authorities meant the information was not leaked to the Internet.

“We hope that women will be reassured that no data’s been released,” she said.

Fitzgibbon said the hacker — who her organisation described as an “an anti-abortion extremist” — launched some 26,000 attacks on the website over a six-hour period Thursday. She said her group was able to trace the online onslaught to a Twitter user and alerted police, who swooped in on their suspect in the early hours of Friday morning.

Scotland Yard said that its specialist e-crimes unit had searched an address in Wednesbury, a market town about 200 kilometres northwest of London, and arrested a 27-year-old man who claimed allegiance to Anonymous, the amorphous Internet activist group.

Detective Inspector Mark Raymond said in a statement that his unit moved rapidly “to prevent personal details of people who had requested information from the (charity’s) website being made public.”

The suspect, who was not identified, remains in custody.