England defender Kieran Trippier told a friend to "lump on" (bet heavily) his transfer from Tottenham Hotspur to Atletico Madrid, according to a written statement by the English Football Association's independent regulatory commission published Tuesday.
Trippier was banned for 10 weeks and fined £70 000 in December for breaching betting rules, although his punishment has been suspended pending an appeal.
The former Spurs star - who was one of England's standout performers in their run to the 2018 World Cup semi-finals - denied the charges against him.
In the written reasons for its decision, the FA said Trippier, 30, exchanged WhatsApp messages with friends about his impending move to Spain in 2019.
The commission rejected Trippier's assertion they were simply "banter" - a jokey claim not to be taken seriously and he was found guilty of four of the seven charges he faced.
Trippier allowed the FA to examine his mobile phone and in July it was revealed that his friend, Oliver Hawley, placed 10 separate bets, ranging from 20 to 65, on the full-back joining Atletico.
After placing one bet, Hawley sent Trippier a message that said: "6/1 Athletico (sic) Madrid", to which Trippier responded with three laughing emojis.
And on July 12, Trippier texted Hawley: "It's happening", shortly before Hawley placed two further bets on the defender's move to the Spanish capital club.
Two days later, another friend, Matthew Brady, texted Trippier to ask: "Shall I lump on you going there (Atletico)?". Trippier later replied: "Lump on if you want mate."
More bets were place by Hawley and two other friends before a transfer for a fee in the region of £20 million was announced on 17 July.
Trippier's ban related to rule E8(1)(b), which states: "Where a participant provides to any other person any information relating to football which the participant has obtained by virtue of his or her position within the game and which is not publicly available at that time, the participant shall be in breach of this rule where any of that information is used by that other person for, or in relation to, betting."
The commission said it took into account witness statements on behalf of Trippier from, among others, England manager Gareth Southgate, captain Harry Kane, adding that the player's good disciplinary record, character and the remorse he demonstrated were also factors in its decision.