Gupta, 53, had been to Sunderbani, close to the Line of Control (LoC) in Rajouri district, for two days on March 28 and 29 this year, intelligence sources said. Officials said they do not have exact information on the kind of relationship the diplomat had with the doctor couple.
"At some stage, it might be investigated," an intelligence official said.
Gupta, a second secretary with the Indian High Commission in Islamabad, has been remanded to police custody. The Indian government Tuesday said it was questioning Gupta for passing sensitive information to Pakistan.
She was arrested four days ago after being summoned to Delhi on the pretext of consultations.