Arobieke is believed to be of Nigerian extraction and was nicknamed Purple Akie because of the darkness of his skin.
Rugby chiefs are worried about the welfare of some of the game's brightest prospects.
Youngsters who've been bothered include Warrington first team players Warren Stevens, 18, Chris Holden, 20, and reserve Liam Bretherton, 17.
Oldham back Jimmy Cowans, 21, has also complained to his club.
Arobieke once lifted 6ft, 17-stone prop Stevens off the ground, threw him over his shoulder and did squat exercises with him.
Bretherton has had a brick hurled through his window. Holden's car was damaged.
Cowans was told a letter bomb would be pushed through his front door and three cars were paint-stripped outside the home of Oldham's safety officer, Roger Norris.
The game's bosses are so worried they are urging certain players to carry mobile phones at all times.
Mr Smith, 57, said: "Arobieke is a very intimidating man - he is absolutely huge.
"These lads are young, fit and strong and you would think they could look after themselves. But they are all very scared.
"Sometimes he tells them to meet him and when they refuse he starts calling at their houses."
