The government has settled with former civil servant Sir Philip Rutnam over his claim for unfair dismissal.
Sources close to Sir Philip confirmed to BBC Radio 4's PM that he received
£340,000 plus his legal costs.
Labour's shadow home secretary Nick Thomas-Symonds said: "Taxpayers will be appalled at having to pick up the bill for the home secretary's unacceptable behaviour."
Sir Philip said Home Office staff had come to him with allegations against Ms Patel, including "shouting and swearing" and "belittling people".
His resignation led the Cabinet Office to launch an inquiry into whether Ms Patel had broken the code governing ministers' behaviour.
Boris Johnson's standards chief Sir Alex Allan found that she had - but the PM rejected his findings and kept her in post. Sir Alex resigned in response.
In his report, Sir Alex found Ms Patel's "approach on occasions has amounted to behaviour that can be described as bullying in terms of the impact felt by individuals."
"To that extent her behaviour has been in breach of the ministerial code, even if unintentionally," he concluded.
The FDA union, which represents senior civil servants, has launched legal action to try and get Mr Johnson's decision overturned at the High Court.
Mr Johnson said he did not think Ms Patel was a bully, and had "full confidence" in her.