Srinagar, April 21 -- A US national and his companion, who were detained at Srinagar International Airport on Sunday after a GPS device was recovered from one of the luggages, have been released after nothing was found suspicious, police said on Monday. However, the police have retained the device for further analysis. "They have been allowed to go and return (to Delhi). There was nothing suspicious to hold them back," said incharge of police post Humhama, Mohammad Adil. "The issue has been closed with 'nothing to report'," he said. The two were questioned by airport security on Sunday and later handed over to the police for further investigation. Officials said that the US national is from Montana while his companion is originally from Kolkata but currently lives in the US. They were reportedly travelling from Srinagar to Delhi. The officer said that the two were questioned about the purpose of their visit as well as the nature of the device which was suspected to be a satellite communicator . "The device is a GPS device not a satellite phone," he said. " We have retained the device for further analysis," he said. Satellite phones such as Thurraya or Iridium are not allowed in border states such as Jammu and Kashmir without prior authorisation. A senior police officer told HT that they were carrying a banned device. This confirms with the US Embassy advisory on its website stating "possession of satellite phones and other GPS devices is strictly prohibited in India and may lead to detention, fines, or arrest." Adil said that the duo have travelled widely and used the GPS device for location in remote areas. "The device is used in forest areas or for tracking purposes," he said. "They have travelled to various countries and would carry the device to every place," he added. He said that they have not been trekking in Kashmir....