The Ministry of External Affairs (MEA) is working with investigative authorities in the case relating to the Uttar Pradesh police arresting an Indian embassy staffer posted in Moscow for allegedly spying for Pakistan's intelligence agency ISI, official sources said on Sunday.

The Anti-Terrorist Squad (ATS) of Uttar Pradesh Police arrested Satendra Siwal, a resident of Shahmahiuddinpur village in Hapur district of Uttar Pradesh, in Lucknow after questioning.

The MEA is aware of the arrest of Satendra Siwal in Uttar Pradesh. He was posted as a Security Assistant in the embassy of India, Moscow, the sources said.

"MEA continues to work with the investigative authorities in the matter," said a source.

In a statement, the UP ATS said Siwal was arrested on charges of working for ISI.

An FIR has been registered against Siwal at ATS police station, Lucknow, under Section 121A of the IPC (waging war against the country) and the Official Secrets Act, the statement said.

Siwal was employed as a Multi-Tasking Staff (MTS) at the MEA.