The 49-year-old was arrested in Salford on Tuesday evening.
A man has been arrested in connection with the terrorist attack at the Heaton Park Hebrew Congregation Synagogue in October last year, police said.
A 49-year-old man was arrested in Salford on Tuesday evening on suspicion of failing to disclose information regarding terrorist activity, contrary to S38B of the Terrorism Act 2000, Greater Manchester Police said.
He has been taken into custody for questioning.
