India will expel a Pakistani high commission staff member for "espionage activities", a foreign ministry official said Thursday, as local media reported that New Delhi police had detained him.

"FS (foreign secretary) summons Pak High Commissioner to convey that Pak High Commission staffer has been declared persona non grata for espionage activities," foreign ministry spokesman Vikas Swarup said on Twitter.

Tensions between India and Pakistan have soared since a raid last month on an Indian army base near the de-facto border dividing Kashmir killed 19 soldiers, the worst such attack in years.

India pointed the finger of blame at militants in Pakistan and said it had responded by carrying out strikes across the heavily-militarized Line of Control, although Islamabad denies these took place.

Delhi police crime commissioner Ravindra Yadav said the official had been detained on Wednesday with defence and other documents in his possession.

The documents included information on deployment of India's border security forces, Yadav told a press conference.

A Pakistani diplomatic source said the visa official, named as Mehmood Akhtar, had been given 48 hours to leave the country.

Pakistan's High Commissioner Abdul Basit lodged a "strong protest" with the Indian foreign ministry and said the detention contravened diplomatic conventions, the source said.

"Pakistan never engages in activity that is incompatible with its diplomatic status," he said.

Kashmir has been divided between India and Pakistan since their independence from Britain in 1947. Both claim the territory in full and have fought two wars over the mountainous region.