Four-time Olympic champion Mo Farah has insisted he has "no tolerance for anyone who breaks the rules" after his former coach Alberto Salazar was handed a four-year suspension by the United States Anti-Doping Agency.

USADA found Salazar and Dr Jeffrey Brown guilty of multiple doping violations during their time working at the Nike Oregon Project (NOP).

Two independent three-member panels found Salazar and Brown trafficked the banned performance-enhancing drug testosterone and attempted to administer a prohibited method to multiple track and field athletes.

Salazar was also found to have "tampered and/or attempted to tamper with the doping control process".

In a statement via the NOP website, Salazar said he was "shocked" by an "unfair" outcome to the investigation and claimed USADA had subjected him to "unjust, unethical and highly damaging treatment".

The 61-year-old coached Farah for six years until their split in 2017, during which time the British long-distance star completed Olympic doubles at 5000m and 10000m in 2012 and 2016.

Reacting to Salazar's punishment, Farah expressed relief that a conclusion had been reached.

"I'm relieved USADA has, after four years, completed their investigations into Alberto Salazar," the 36-year-old said in a statement.

"I left the Nike Oregon Project in 2017 but, as I've always said, I have no tolerance for anyone who breaks the rules or crosses a line.

"A ruling has been made and I'm glad there has finally been a conclusion."

Following USADA's ruling, the IAAF circulated a short statement in which it confirmed Salazar's accreditation for its ongoing World Athletics Championships in Doha had been revoked.

Farah began working with Salazar in the same year he claimed a first global title by winning the 5000m at the 2011 World Championships.

He took silver in the 10000m and, in between his corresponding Olympic heroics, won the long-distance double at both the 2013 and 2015 World Championships.

Another worlds gold followed in the 10000m at London 2017, although he was forced to settle for 5000m silver.

After the event, Farah announced his relocation to the English capital to work under coach Gary Lough – his focus shifting full-time to marathon running – but maintained the switch was nothing to do with doping allegations hanging over Salazar.

UK Athletics conducted a review of Farah's working relationship with Salazar in 2015 following allegations made against the coach by BBC's Panorama programme. It found "no reason" to doubt its confidence in the NOC.

A statement issued by UK Athletics on Tuesday read: "The Board of UK Athletics acknowledges the announcement made by USADA concerning the four-year sanction imposed on Alberto Salazar.

"The Board and Performance Oversight Committee (POC) will now review the arbitration decision in full prior to making any further comment.

"It should be noted that at all times UK Athletics fully cooperated with both USADA and UKAD throughout the investigations. Furthermore the Performance Oversight Committee's own investigation in 2015 was restricted to the interaction of the Nike Oregon Project with Mo Farah. and not an anti-doping investigation.

"Such investigations can and should only be undertaken by the relevant anti-doping authorities.

"UK Athletics is 100 per cent committed to clean athletics through investment in athlete education, supporting comprehensive testing programmes, and full cooperation with both UK and International Anti-Doping Authorities."