Forest Green said the Gambling Commission had found "insufficient evidence" to prosecute.
Rovers will now write to the Football Association to ask how such allegations can be handled better in future.
"Both clubs and their players have been smeared for a whole year with apparently no substance behind some of the lurid tabloid headlines," Forest Green vice chairman Colin Peake told the club website.
We are pleased that the club has been exonerated but more importantly we are pleased for those players who played in the match
Forest Green vice chairman Colin Peake
"The FA needs to urgently address the whole subject of reports made by betting companies when they believe they see irregular betting patterns emerging on football matches.
"In the case of this match, why was it the only one referred to in the investigation when we learned other games also had betting suspended the same weekend?"
The game in question saw Grays defeat Forest Green 2-1. The teams face each other again on Saturday.
Peake added: "We are pleased that the club has been exonerated but more importantly we are pleased for those players who played in the match."
Source: BBC Sport
Source: BBC Sport