World 5,000m silver medallist Mohamed Katir has received a four-year ban for tampering after he was found to have falsified travel documents submitted during an investigation into missed doping tests.

The 26-year-old Spaniard was suspended for two years by the Athletics Integrity Unit (AIU) in February for missing three doping tests in 12 months.

But during its investigation the AIU discovered that on the date of one of those missed tests, 28 February 2023, Katir had altered his travel itinerary, boarding pass and booking confirmation in an attempt to mislead investigators who were looking into where he was that day.

The AIU requires athletes to log their 'whereabouts', external to assist unannounced out-of-competition tests.

The four-year ban will run concurrently with Katir's previous sanction, extending his suspension until February 2028.

"There can be no doubt that the athlete put forward a false version of events and altered documents," concluded the AIU's disciplinary tribunal.

"He did so in order to persuade WA (World Athletics) that his filing failure on 28 February 2023 should not be treated as a whereabouts failure."

Katir, who won World Championship bronze in the 1500m in 2022 and silver in the 5,000m in 2023, will miss the Worlds in Tokyo next year and Beijing in 2027.

The AIU asked for Katir's results from 9 March 2023 onwards to be disqualified but that was rejected by the disciplinary tribunal because the timing of his whereabouts failure did not offer a "competitive advantage which affected his results".

The head of AIU Brett Clothier said the ruling underscored the seriousness of tampering.

"Gone are the days in athletics when explanations offered in anti-doping cases are just accepted at face value," said Clothier.

"Thanks to strong investment in investigations, since its inception in 2017, the AIU has prosecuted 25 tampering cases.

"The vast majority of our elite athletes respect the strict rules and processes of the sport and they should take heart at the action being taken to ensure a level playing field."