Neither airport would comment on the specific technology they are investing in.
Media reports suggested earlier on Thursday that the defense ministry had removed its anti-drone hardware from Gatwick.
London's Gatwick and Heathrow airports have ordered military-grade anti-drone defences worth "several million pounds" after drones caused three days of disruption at Gatwick last month, The Times newspaper reported on Thursday.
It is understood that a meeting between bosses of all United Kingdom airports and aviation minister Baroness Sugg will take place next week to establish what measures other hubs have taken since the Gatwick incident.
"The Armed Forces stand ever-ready to assist should a request for support be received".
A Heathrow spokesperson said: "The safety of our passengers and colleagues remains our top priority".
Military equipment was installed at Gatwick in December to prevent disruption caused by drones flying over the airfield. It said it was working closely with authorities including the police and looking at relevant technology to combat the threat of drones.
A spokesman for manufacturer Rafael told The Times newspaper there had been a lot of interest in the product from the authorities in the United Kingdom and other nations, but declined to confirm whether Gatwick had bought a system.
Sussex Police continues to progress a thorough and comprehensive criminal investigation into the illegal drone activity at Gatwick, which led to airport disruption.
More than 1,000 house to house enquiries have also been carried out by officers. Skylock, the company that manufactures the technology, is one of many now specializing in detecting and downing intruder drones by "jamming" them, or disrupting their frequencies.
Two people, a middle-aged couple who lived near Gatwick, were arrested over the suspected "criminal use of drones" but later released without charge.