In a statement released by the Stags today, they’ve confirmed they’re still investigating an ‘an alleged serious breach of club discipline.’
Donohue departed Fratton Park at the end of last season after making 50 appearances following his arrival from Chesterfield for an undisclosed fee in August 2017.
He moved to the Field Mill on a free transfer in July.
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Earlier this week, Mansfield announced the Welshman and team-mate Jacob Mellis had been suspended, stating neither player was available for training or selection for games.
The League Two side have confirmed Mellis has been issued a two-week fine for breaching club regulations.
But Donohue remains under investigation.
A Mansfield statement said: ‘The club has applied a two-week fine – the maximum available to the club – to midfielder Jacob Mellis following a breach of club regulations and has warned Jacob of his future conduct.
‘Mansfield Town Football Club will not compromise on the high standards of conduct it expects at all times from its employees.
‘An investigation is ongoing into the alleged serious breach of club discipline by Dion Donohue. The midfielder remains suspended during this investigation.
‘The club will be making no further comment.’