Having found this excerpt in the Jewish Encyclopedia - I wondered whether the Gamaliel referred to, might not be Rabban Gamliel I, Hazaken, and this Joshua 'Jesus' an unacknowledged son, in addition to the more well-known one, Simeon:
"Jesus (Joshua) b. Gamaliel (Gamla) received the high-priestly dignity. A strife ensued between the deposed and the new high priest; they insulted each other in the public streets and even threw stones at each other (ib. § 4), but Jesus b. Gamaliel remained the victor."
Schürer, Gesch. des Jüdischen Volkes, 3d ed., i. 584, ii. 220.
http://jewishencyclopedia.com/articles/8911-joshua-jesus-ben-damnai
@Yigal replied "I am not at all convinced that Raban Gamliel the Elder, who was from Jerusalem, and lived in Jerusalem as the President of the Sanhedrin in named Gamla - a town in the North east of the Kingdom - in the Golan Heights. Also - no evidence from the Jewish Encyclopedia that we know more than two of his children: a daughter (no known name) and a son Shimon ben Gamliel. No mention of a third child Joshua (Jesus). Most probably Joshua's (Jesus) father was another Gamlial (Gamla) - quite a common name."