Lacazette has played his entire professional career at Parc Olympique Lyonnais after making his debut back in 2007, with 85 Ligue 1 goals from 187 appearances.
He has bagged 13 league goals from 14 outings this term and has been attracting the attention of some of Europe's biggest clubs.
West Ham made an unsuccessful attempt to sign him last summer and, according to Aulas, Les Gones will reject the latest offer as they have no intention of parting company with the France international.
"It is true that the offers we have received for Alexandre range from 40m euros - from West Ham last year - to 70m euros right now," he told RMC.
"Obviously, Alexandre is indispensable for us. Just like Nabil [Fekir] and Corentin [Tolisso] and all the other players for whom we have received offers. We have six or seven offers on the table for our best players.
"We have the intention to close the gap with the teams at the top of the table in Ligue 1 and to go far in the Europa League because this could be an opportunity for us."